Russell b



(No Model.)

R. B. HOBSON. FURNACE DOOR.

Patented July 20,1897.

INVENTOR l5.

WITNESSES ATTORNEYS.

nu: nonms PEYERS on, monun'uoq wnsnmmou, D. c

UNITEn STATES PATENT OFFICE.

RUSSELL B. HOBSON, OF NElV YORK, N. Y.

FURNACE-DOOR.

SPECIFICATION forming part of Letters Patent No. 586,552, dated July 20, 1897.

Application filed October 28, 1896.

To all whom it 12mg concern:

Be it known that I, RUSSELL B. HOBSON, of New York city, in the county and State of New York, have invented a new and useful Improvement in F urn ace-Doors, of which the following is a full, clear, and exact description.

This invention relates to lire-box and ashpit doors for the furnaces of steam-boilers, and particularly watertube, pipe, or coil boilers; and the object is to so arrange the door with relation to the furnace that in the event of an exploded tube or pipe the pressure of the escaping contents of the boiler will act to so effectually close the door that the escape of steam, water, or the contents of the fire-box or ash-pit into the fire-room will be prevented, such contents being forced to make exit into the flue or stack.

With the above-stated end in View the invention comprises an inwardly-swinging door and a casing or frame therefor so constructed as to considerably overlap the edges of the door at the outside, thus practically forming a valve and valve-seat.

The invention further consists in the construction and novel arrangement of parts, as will hereinafter appear, and be particularly pointed out in the appended claim.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in both the figures.

Figure 1 is a section on the line 1 1 of Fig. 2 of a furnace-door embodying my improvement, and Fig. 2 is a front elevation thereof.

Referring to the drawings, 1 designates a portion of the front wall of the furnace having a door-openin 2 above the grate-bars 3. At the outside of the furnace-wall and surrounding the opening 2 is a door casing or frame, comprising a forwardly-extended and downwardly-curved hood at at its upper side, downwardly and inwardly inclined flanges 5 at its ends, and a bottom flange 6, all these parts forming a seat 7 to receive and sustain the door.

Arranged within the casing or frame and adapted to swing upward and inward is a door 8, keyed to a shaft 9, having bearings through the end walls 10 of the door-casing. This door has a transversely-curved inwardly-extended top flange 11, designed to fit closely within the hood 4:, a transverselycurved bottom flange 12, adapted to fit closely against Serial No. 610,299. (No modeLl the curved portion of the flange 6, and inwardly-extended end flanges 13, designed to fit closely against the inner surfaces of the sides 10 of the casing or frame.

To the inner side of the door a baifle-plate 14. is attached by means of bolts, and from one end of the shaft 9 an arm is upwardly extended, and adjustably mounted on this arm 15 is a weight 10. It will be seen that the arm 15 is arranged at such an angle relatively to the axis of the shaft 9 that when the door is closed the weight on the arm will be inside a line drawn vertically from the shaft 9, and therefore the weight will serve to hold the door closely against its seat. WVhen the door is swung open bypushing it inward, the weight overbalancing the door will hold it open as long as may be desired.

By the construction described should an escape of steam, &c., occur, as before mentioned, while the door is open the pressure 011 the door will force it to its closed position and press it tightly against the flanges of the easing or frame and thus prevent the escape of such steam, &'c., into the boiler-room, and should the accident occur while the door is closed the same result will obtain.

1 am aware that it is not broadly new to provide a furnace with an inwardly-swingin g door; but such doors and casings have not been so constructed as to prevent the outward escape of the contents of the boiler and fire-box should an accident take place, as described.

Having thus fully described my invention, I claim as new and desire to secure by Letters Patent- The combination with a furnace, of a doorcasing having an outwardly and downwardly curved hood at its upper side, downwardly and inwardly inclined end flanges, and a bottom flange having a transversely-curved inner surface, and a door mounted to swing inward in the casin g and having a transverselycurved top flange to engage in the hood of the casing, a transversely-curved bottom flange to engage the curved surface of the bottom flange of the casing, and inwardly-extended end flanges to engage the side walls of the casing, substantially as specified.

RUSSELL B. HOBSON.

Witnesses:

C. R. FERGUSON, J NO. M. BITTER.

IOO 

